694 research outputs found
Einstein-Yang-Mills AdS Black Brane Solution in Massive Gravity and Viscosity Bound
We introduce the Einstein-Yang-Mills AdS black brane solution in context of
massive gravity. The ratio of shear viscosity to entropy density is calculated
for this solution. This value violates the KSS bound if we apply the Dirichlet
boundary and regularity on the horizon conditions.Comment: 10 pages, accepted by the European Physical Journal
Holographic Aspects of a Higher Curvature Massive Gravity
We study the holographic dual of a massive gravity with Gauss-Bonnet and
cubic quasi-topological higher curvature terms. Firstly, we find the
energy-momentum two-point function of the 4-dimensional boundary theory where
the massive term breaks the conformal symmetry as expected. An -theorem is
introduced based on the null energy condition. Then we focus on a black brane
solution in this background and derive the ratio of shear viscosity to entropy
density for the dual theory. It is worth mentioning that the concept of
viscosity as a transport coefficient is obscure in a nontranslational invariant
theory as in our case. So although we use the Green-Kubo's formula to derive
it, we rather call it the rate of entropy production per the Planckian time due
to a strain. Results smoothly cover the massless limit.Comment: v2: 20 pages, typo corrected, references added; v3: section 2.2
revised; v4: section 2.2 modified, viscosity formula revised, 2 figs added,
references added; v5: 23 pages, a sign mistake in eq. (74) fixed (results
modified), eq. (34) modified, one fig added, refs added, to appear in EPJ
Knowledge-based potentials in protein fold recognition
An accurate potential function is essential for protein folding problem and structure prediction. Two different types of potential energy functions are currently in use. The first type is based on the law of physics and second type is referred to as statistical potentials or knowledge based potentials. In the latter type, the energy function is extracted from statistical analysis of experimental data of known protein structures. By increasing the amount of three dimensional protein structures, this approach is growing rapidly.There are various forms of knowledge based potentials depending on how statistics are calculated and how proteins are modeled. In this review, we explain how the knowledge based potentials are extracted by using known protein structures and briefly compare many of the potentials in theory
Holographic Aspects of Non-minimal AdS Black Brane
In this paper, we study the holographic dual to an asymptotically anti-de
Sitter black brane in an Einstein-Yang-Mills model with a non-minimal coupling
between the Riemann and Yang-Mills fields. First, we construct a planar black
hole solution of this model up to the first order of the non-minimal coupling
of the Yang-Mills field with the Riemann-Christoffel tensor, denoted as .
Then, we calculate the color non-abelian direct current (DC) conductivity and
the ratio of shear viscosity to entropy density for this solution. Our result
for the shear viscosity to entropy density ratio saturates the
Kovtun, Son, and Starinets (KSS) bound, which is proportional to . However, our result for the conductivity is new up to the first order of
.Comment: 11 Pages, no figure, typo corrected, references added, minor
modifications, accepted for publication in CQ
The effect of three matters on KSS bound
Our goal in this manuscript is to introduce black brane solutions in AdS
4-dimensional (4D) Einstein-Gauss-Bonnet-Yang-Mills theory in presence of
string cloud and quintessence. Shear viscosity to entropy density ratio is
computed via fluid-gravity duality, as a transport coefficient for this model.Comment: 10 pages, no figur
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